For cable-stayed bridges and special-shaped tied arch bridges,the cable force of the oblique sling is an important parameter that affects whether the bridge state is reasonable Therefore,it is a key issue in the bridge design stage to determine a reasonable set of bridge cable forces so that the bridge’s completed state meets the design goals of linear smoothness and reasonable internal force distribution.In the actual construction stage,determine a reasonable set of initial construction cable forces to Ensuring structural construction safety and construction accuracy is also the focus of the bridge construction stage.Based on the engineering background of a special-shaped tied arch bridge and a cable-stayed bridge,this paper conducts research on reasonable bridge cable force,initial construction cable force,and cable adjustment cable force.The main research contents are as follows:(1)Based on the basic genetic algorithm,this paper proposes a cable force optimization method combined with an improved genetic algorithm.The genetic algorithm is improved by dividing the gene mutation space,introducing an elite retention mechanism,and setting dynamic mutation operators to solve the cable force optimization problem for the genetic algorithm Improve optimization efficiency.The method steps of genetic algorithm for cable force optimization are given in the article.And based on the data,the finite element model of the simple bridge model was established,and the least displacement square sum method was used for optimization.The optimization results show that the basic inheritance method and the improved genetic algorithm are feasible in searching for the optimal solution.(2)Based on the background of the Xuxi Bridge under the special-shaped tied arch bridge and the special-shaped cable-stayed pedestrian bridge,finite element modeling and analysis calculations are carried out according to the design data.The cable force is used as a variable of the genetic algorithm,the weighted bending energy of the tower beam,the square sum of bending moments,and the square sum of displacement are used as the design goals,and the displacement and stress values of the key sections are used as constraints.Improve the optimization of genetic algorithm,and compare the optimized cable force and the bridge state.The results show that the cable force optimization method adopted in this paper is reasonable and effective,and the improved genetic algorithm has a higher optimization efficiency,and it is suitable for both special-shaped cable-stayed bridges and special-shaped tied arch bridges.(3)Based on the design and construction data of the Xuxi Bridge under the special-shaped tied arch bridge and the special-shaped cable-stayed pedestrian bridge,the finite element model of the construction stage is established.In this paper,the initial installation force is solved by the forward installation iteration method combined with the improved genetic algorithm.Comparing the two methods,the improved genetic algorithm can also solve the problem of cable force optimization in the construction phase.According to the possible cross-sectional size errors,temporary construction loads,temperature changes and other factors in the construction stage,the construction error optimization model is established,and the improved genetic algorithm is used to adjust the cable force.The results show that the improved genetic algorithm is equally effective in the construction error optimization problem.